Also, don't underestimate the adversaries. Ranking well on Google means earning a lot of money. So much so, that I'd argue the SEO-people are making significantly more money than Google loses by having spammy SERPs. They will happily throw money at the problem and work around the filters. I don't think you can really select for quality by statistical measures. Google tried and massively threw "trust" at traditional media companies and "brands". The SEO-people responded by simply paying the media companies to host their content, and now they rank top 3, pay less than they did by buying links previously, and never get penalties.

They already do this today for any venue where they can link “traffic volume” to “ranking increase without human review”.

That might explain a lot but I don't think so.

Just look to how they are messing up simple searches because of basic lack of quality controls:

- Why doesn't doublequotes work anymore? Not because dark SEO vut because nobody cares.

- Same goes for the verbatim option.

- The last Android phone I liked was the Samsung SII, and last year I finally gave up and got the cheapest new iPhone I could get, an XR. My iPhone XR reliably does something my S3, S4, S7 Edge and at least one Samsung Note couldn't do: it just work as expected without unreasonable delays.

- Ads. They seem to be optimized to fleece advertisers for pay-per-views because a good number of the ads I've seen are ridiculous, especially given that I had reported those ads a number of times. I guess what certain customers that probably paid a lot for those impressions would say if they knew that I had specifically tried to opt out from those ads and weren't in the target group anyway.

Google's aim was to replace other sources of information with Google:

> People make decisions based on information they find on the Web. So companies that are in-between people and their information are in a very powerful position

Profit was on their minds from the very beginning:

> There are a lot of benefits for us, aside from potential financial success.

Revenue, however, was not urgent back then, to them or to their VCs:

> Right now, we’re thinking about generating some revenue. We have a number of ways to doing that. One thing is we can put up some advertising.

So over the past two decades, they executed a two-pronged approach: Become indispensable and Become profitable. But now they're trying to pivot from "at web search" to "at assisting human beings", and that's a much more difficult problem when their approach to "Become profitable" was to use algorithms rather than human beings.

Here's a useful litmus test for whether Google has succeeded at that pivot:

If you were in a foreign city and you suddenly wanted to propose marriage to your partner, would you trust Google Assistant to help you find a ring, make a dinner reservation, and ensure that the staff support the mood you want (Quiet or Loud, Private or Public)?

If so, then Google's pivot has been successful.